A morpholine derivative, chemical name: methyl (3-(3-((R)-1-((R)—N-cyclopropylmorpholine-2-carboxamido)ethyl)-6-methyl-1H-pyrazolo[3,4-b]pyridin-1-yl)n-propyl)carbamate, molecular formula: C22H32N6O4, has the following structural formula:

CN103562191 (201280013626.5) discloses a free base form of the morpholine derivative, its preparation method and its renin inhibitory activity. The free base is a semi-solid or amorphous powder and shows poor water solubility, and it is relatively easy to be oxidized and thus not suitable for long-term storage.